Magnetic disc recorders, or file assemblies, known and used heretofore usually provide for two entirely separate air flow paths within the assembly, particularly where rigid or "hard" discs are used, as is most often the case. One such air flow path is used for cooling motors and other heat-producing elements of the assembly, and the other air flow path is used for aerodynamically supporting a read/write head on a thin film of air passing over the head and across the rotating disc. The head is shaped so that air passing between the head and the disc lifts or supports the head, thereby aerodynamically "flying" it above the surface of the disc. The reason for separating the two air flows is the important requirement for one such path of keeping all contamination away from the head and disc. The air passing over the head and disc must be cleaned and filtered and is usually recirculated within a closed system. In contrast, the air for cooling is typically not in a closed system, since there is no requirement that such air be free of contaminants, and a relatively large volume of ambient air is typically drawn from the immediate area, forced through the air flow path to provide for cooling, and then expelled into the environment.
Such a division of air flow paths is disadvantageous in many ways, because at least two completely different air-moving means must be used and of course separate structures must be used to define the dual air paths. Since the paths must be mutually exclusive, the complexity of the two different paths adds considerably to the difficulty and expense of manufacturing.